1. Field of the Invention
The present invention relates to a method of mounting components onto a substrate, that is, a method of equipping a substrate with components. In particular, a method for mounting electrical components onto a substrate, such as, a circuit board.
2. Description of the Prior Art
During known component mounting or equipping methods, such as, mounting components onto a circuit board, the components are removed from a number of supply units via a component mounting head member. Once removed, the component mounting head member then places or mounts the component onto the substrate at a predetermined position. There exists a need in the art to have the components placed or mounted onto the substrate at an increased or optimal component mounting rate, that is, an increased number of mounted components per unit time.
The International Patent No. WO 98/37744 provides a device for manufacturing an electrical assembly. This device has two longitudinal guides that extend parallel and closely together along a central component mounting process area for receiving a respective carriage that can then move along the guides. Each of the carriages includes a mounting element that is adapted for accepting a respective component mounting head member. In this way, each of the component mounting head members can operate independently of one another wherein a component mounting process area exists for the operation of each of the component mounting head members. With two, independently-operating component mounting process areas, the component mounting rate can, thus, be increased.
In order to realize an increased component mounting rate, a number of automatic component mounting units that each have a component mounting head member for receiving and mounting the components and that are positioned in an assembly-line manner have been utilized. Each of the automatic component mounting units also includes a component supply member wherein each of the automatic component mounting units can be dedicated to mount particular type of component. In this way, a respective component mounting process area is designated for each of the component mounting units wherein the mounting process for a particular substrate is divided amongst each of the component mounting units, that is, each of the component mounting units operates to mount a different component onto the substrate.
In order to decrease down time and thereby increase the component mounting rate, such as, from the time it takes to move the substrate from one process area to the next, two transport members are utilized. However, a high percentage of down times still exists in substrates that have a low mounting or placement content (less than about 100 components) due to the need to newly measure or calibrate the reference marks on the substrate after transport into the next processing area along the assembly line. Still further, a lower component mounting efficiency or rate results from an under utilization of the holding element of the component mounting head member. Typically, the holding element includes a number of holding elements, such as, twelve to eighteen suction pipettes. An under utilization occurs when only a portion of the holding elements are utilized for receiving and mounting a component where the amount of time to mount the components is essentially the same whether all or only a portion of the holding elements are utilized.
It is an object of the present invention to provide a method for mounting or equipping a number of components onto a substrate that results in an increased component mounting rate or efficiency. It is still further an object of the present invention to provide a method for mounting a small number of components, such as, one hundred or fewer components, onto a substrate while realizing increased and optimal component mounting or equipping rates.
The present invention provides a method for mounting a number of components that employs a number of component mounting process areas that are successively positioned in an assembly-line manner. Each of the component mounting process areas includes a component mounting head member for mounting a number of components onto the substrates and a number of supply units, each containing only components of one component type, for supplying the component mounting head members with the components. The present invention further employs a transport member for moving each of the substrates to each of the component mounting process areas.
In an embodiment, the present invention includes at least a first and second component mounting process area or processing areas.
In an embodiment, the component transport member includes a first and second transport member for moving a respective number of components.
In an embodiment, the substrates are completely mounted or equipped with a number of components having a number different component types during a single stage component mounting process when the number of different component types to be mounted is less than or equal to a number of supply units, that is, the number of different component types is small in number. By utilizing a single stage mounting process, the component mounting rate is optimally increased by eliminating the need to newly calibrate or measure the component mounting head member or equipping head relative to the substrate in each of the successive component process areas and by optimal utilization of the component mounting head member. When the number of different component types to be mounted is greater than the number of supply units, that is, when the number of different component types is large in number, a multiple stage component mounting process is utilized wherein the number of different component types are completely mounted onto the substrate in at least the first and second component process areas.
In an embodiment, the substrates are completely mounted with a number of different component types during a single stage component mounting process at one of the first or second component mounting process areas when the number of different component types to be mounted is less than or equal to a number of supply units, that is, the number of different component types is small in number and when the time difference between mounting or equipping components in the first and second process areas is positive. If the time difference is negative or the number of different component types to be mounted is greater than the number of supply units, then a multiple stage mounting process is utilized.
In an embodiment, the transport member includes a first and second transport member each for transporting a respective portion of the substrates between at least the first and second component mounting process areas.
In an embodiment, at least the first and second component mounting process areas includes a first and second group of supply units that are disposed adjacent to the first and second transport members, respectively, so as to further increase the efficiency or rate of mounting components onto the respective substrates.